Why isn't Kennen played as ADC much?

Why isn't Kennen played as ADC much?

I've been wondering why he isn't played as an ADC anymore (I recall hearing he used to be) he seems to have a good enough kit for it: his E gives him a good escape, his Q does nice early damage, and his passive combined with his ult let's him lock down the enemy adc for a fair amount of auto-attacks. I know he's played by Giants in the EU LCS, but why isn't he played by everyone else?

EDIT: The phrase "Don't knock it 'til you try it" carries over here. At least try it a game or two before dismissing it.

He's also decent as an ADC because he has some nice poke and a decent steroid on his W passive, but his ult doesn't really do anything for him at all since he's supposed to be positioning himself outside of the commotion like all ADCs since he's squishy.

I supposed that he could press R when a bruiser dives him to hopefully get a stun off whilst he orbwalks but that's wasting his full potential on R.

He's also decent as an ADC because he has some nice poke and a decent steroid on his W passive, but his ult doesn't really do anything for him at all since he's supposed to be positioning himself outside of the commotion like all ADCs since he's squishy.

I supposed that he could press R when a bruiser dives him to hopefully get a stun off whilst he orbwalks but that's wasting his full potential on R.

Kennen is just...in a really weird spot right now.

From what I've played in Kennen ADC before, his ulimate is fantastic for getting a kill in lane. And you're right, his ultimate is used more for keeping himself safe than anything, but if your team is winning the fight, it really helps with clean up.